The invention relates to a coating process for the coating of an interior of a pipework system, as well as to a sub-distributor and a working equipment for the treatment of a pipework system in accordance with the preamble of the independent claim of the respective category.
Such processes are used for drying oxidizing or otherwise corroding water pipes in buildings, for derusting them by means of sand blasting, and for coating them subsequently with an epoxy resin coating or with an other plastic layer.
Mostly, water pipes of a building are subdivided in several pipelines. A typical example is a pipeline in a plumbing unit in an apartment or in a house. Water pipes for cold water constitute a first pipeline leading to a water-closet, a bathtub, a washbasin, and a shower. Water pipes for hot water leading to a washbasin, a bathtub, and a shower constitute a second pipeline. The water pipe for hot water is supplied by a hot water boiler. The pipes establishing the pipelines for hot water can corrode and rust, too. Further pipelines in houses and apartments are in the kitchen and in the laundry, are constituted by pipeline systems for heating installations and so on.
Nowadays, the most common application of known working processes is the coating of cold water pipes and pipelines in buildings. Regarding buildings, a frequently given coating problem is that no building plans for the sanitary pipeline system are available. And if such building plans are available, the pipes are very often installed different from that shown in the building plans. Regarding the coating processes known so far, this can have the consequence that some pipe sections are not coated. Later on, this problem will be highlighted with the help of FIG. 3 and FIG. 4. Regarding known processes, the still fluid coating material is blown into each connecting pipe, for example into the pipes for the toilet, the washbasin, and the bathtub at the same time. Thereby, an amount of coating material is blown into each connecting pipe which amount was determined from the length and the diameter of the pipes given in the building planes.
In case that the effective length of pipes is identical to the length determined from the building planes, it can be assumed that the coating is perfect. But it happens that the pipes used have an inner diameter which is completely or partly greater than assumed so that the calculated amount of coating material is not sufficient and a greater amount of coating material would be necessary for a perfect coating.
Also the contrary happens in practice, namely the amount of epoxy resin was calculated to much because the pipes are completely or partly thinner than assumed, or the length of the pipes is actually shorter than assumed, leading to that too much coating material is blown into a particular pipe section so that the inner surface of the pipe is coated too thick, or in an extreme example the pipe is clogged by the coating material.
Regarding the existing processes, there is no possibility to determine whether the pipeline is perfectly coated by the coating material, or whether the thickness of the coating has the preset reference value, respectively.
But also the preparation processes known from the state of the art which must be carried out beforehand the actual coating process have disadvantages not being eliminated until now.
Regarding this, the pipework system must be completely dewatered and dried in a first step. With regard to the known processes, after having drained the water being in the pipes at the lowest point, hot air is simply blown into the pipework system at one or more access points for a given period of time. Very often, in particular if the pipework system comprises a lot of bendings, the water is not completely drained since the water is retained in the bendings of the pipework system and, thus, is not blown out.
Strongly related problems are present at the following sand blasting of the pipework system. Regarding this, in particular the bendings are often only insufficiently cleaned by the sand blasting process or critical locations are reached not at all. In addition, the known processes have to work with high blasting pressures, in particular to get the problems at bendings under control, which, in case of thin or already strongly worn-out pipes, leads very often to the situation that the pipes are positively shot-through at the bendings by the sand blasting process, in turn leading to that the masonry in which the pipes are installed must be broken open, and the old pipes must be replaced by new ones, what actually should be avoided by the coating process.
Problems similar to the afore described in connection with the draining of the pipework system also consequently arise when dedusting the pipework system which must be done after the sand blasting process and before coating.
It is thus an object of the invention to suggest an improved coating process which renders possible to ensure in a controllable manner that all parts of the pipework system to be coated are coated having a preset thickness.
It is furthermore an object of the invention to provide an equipment with which the working process as well as the coating process can be carried out in a reliable, cost-effective, and simple way, preferably in a completely automated manner.